ON THE COMPUTATION OF COVERT CHANNELCAPACITY

We address the problem of computing the capacity of acovert channel, modeled as a nondeterministic transducer. We givethree possible statements of the notion of “covert channel capacity”and relate the different definitions. We then provide several methodsallowing the computation of lower and upper bounds for the capacityof a channel. We show that, in some cases, including the case of inputdeterministicchannels, the capacity of the channel can be computedexactly (e.g. in the form of “the largest root of some polynomial”)